/*******************************************************************************
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package ai.platon.pulsar.crawl.index;

import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.time.Instant;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.stream.Collectors;

/**
 * This class represents a multi-valued field with a weight. Values are
 * arbitrary objects.
 */
public class IndexField implements Writable {
    private float weight;
    private List<Object> values = new ArrayList<>();

    public IndexField() {
    }

    public IndexField(Object value) {
        this(value, 1.0f);
    }

    public IndexField(Object value, float weight) {
        this.weight = weight;
        if (value instanceof Collection) {
            values.addAll((Collection<?>) value);
        } else {
            values.add(value);
        }
    }

    public void add(Object value) {
        values.add(value);
    }

    public float getWeight() {
        return weight;
    }

    public void setWeight(float weight) {
        this.weight = weight;
    }

    public List<Object> getValues() {
        return values;
    }

    public List<String> getStringValues() {
        return values.stream().map(Object::toString).collect(Collectors.toList());
    }

    public void reset() {
        weight = 1.0f;
        values.clear();
    }

    @Override
    public Object clone() throws CloneNotSupportedException {
        IndexField result = (IndexField) super.clone();
        result.weight = weight;
        result.values = values;

        return result;
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        weight = in.readFloat();
        int count = in.readInt();
        values = new ArrayList<>();
        for (int i = 0; i < count; i++) {
            String type = Text.readString(in);

            if (type.equals("java.lang.String")) {
                values.add(Text.readString(in));
            } else if (type.equals("java.lang.Boolean")) {
                values.add(in.readBoolean());
            } else if (type.equals("java.lang.Integer")) {
                values.add(in.readInt());
            } else if (type.equals("java.lang.Float")) {
                values.add(in.readFloat());
            } else if (type.equals("java.lang.Long")) {
                values.add(in.readLong());
            } else if (type.equals("java.util.Date")) {
                values.add(new Date(in.readLong()));
            } else if (type.equals("java.time.Instant")) {
                values.add(Instant.ofEpochMilli(in.readLong()));
            }
        }
    }

    @Override
    public void write(DataOutput out) throws IOException {
        out.writeFloat(weight);
        out.writeInt(values.size());
        for (Object value : values) {

            Text.writeString(out, value.getClass().getName());

            if (value instanceof Boolean) {
                out.writeBoolean((Boolean) value);
            } else if (value instanceof Integer) {
                out.writeInt((Integer) value);
            } else if (value instanceof Long) {
                out.writeLong((Long) value);
            } else if (value instanceof Float) {
                out.writeFloat((Float) value);
            } else if (value instanceof String) {
                Text.writeString(out, (String) value);
            } else if (value instanceof Date) {
                Date date = (Date) value;
                out.writeLong(date.getTime());
            } else if (value instanceof Instant) {
                Instant date = (Instant) value;
                out.writeLong(date.toEpochMilli());
            }
        }
    }

    public String toString() {
        return values.toString();
    }
}
